In some commercial warewash machines, drain water is at a temperature above that mandated by plumbing codes for draining. This is because cleaning water and rinse water are typically above this temperature during a cleaning operation. In order to cool the drain water, cold water is sometimes flushed down the drain with the drain water to lower water temperature.
Energy efficiency continues to be a significant issue in the field of warewash machines, particularly commercial warewash machines that tend to be high volume machines. It is known to provide heat recovery systems for recovering some heat from drain water that is being purged from the machine as exemplified by U.S. Pat. No. 5,660,193.
Nonetheless, it would be desirable to provide a warewash machine with a new and advantageous waste water energy recovery system.